nodejs custom events

events.js

var events=function(){
    this.map={};
};
events.prototype={
    emit:function(eventname,args){       
        if(this.map[eventname]){
            this.map[eventname].forEach(function(fn){
                fn.apply(this,args);
            });
        }
    },
    on:function(eventname,callback){
        if(this.map[eventname]){
          this.map[eventname].push(callback);
        }else{
          this.map[eventname]=[callback];    
        } 
    }
}

var test=function(){
    events.call(this);    
}

test.prototype=Object.create(events.prototype,{
   run:{
     value:function(n){
        var i=0;
        while(i<n){
            i++;
            console.log(i);
            if(i===5) this.emit('five',[i]);
        }
     } 
   }
});

var myEventTest=new test();
myEventTest.on('five',function(i){
    console.log('five fired on '+i);
});
myEventTest.run(8);